Automatic drain valve



FIG. 1 is a front, top and right side perspective view of an automatic drain valve showing a first embodiment of my new design;

FIG. 2 is a rear, bottom and left side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a left side view thereof;

FIG. 8 is a right side view thereof;

FIG. 9 is a front, top and right side perspective view of an automatic drain valve showing a second embodiment of my new design;

FIG. 10 is a rear, bottom and left side perspective view of FIG. 9;

FIG. 11 is a front view of FIG. 9;

FIG. 12 is a rear view of FIG. 9;

FIG. 13 is a top plan view of FIG. 9;

FIG. 14 is a bottom plan view of FIG. 9;

FIG. 15 is a left side view of FIG. 9; and,

FIG. 16 is a right side view of FIG. 9. 

CLAIM The ornamental design for an automatic drain valve, as shown. 